Multiparametric magnetic resonance imaging (MRI) and subsequent MRI/ultrasonography fusion-guided biopsy increase the detection of anteriorly located prostate cancers

A multi-object deep neural network architecture to detect prostate anatomy in T2-weighted MRI: Performance evaluation

Prostate gland segmentation is the primary step to estimate gland volume, which aids in the prostate disease management. In this study, we present a 2D-3D convolutional neural network (CNN) ensemble that automatically segments the whole prostate gland along with the peripheral zone (PZ) (PPZ-SegNet) using a T2-weighted sequence (T2W) of Magnetic Resonance Imaging (MRI). The study used 4 different public data sets organized as Train #1 and Test #1 (independently derived from the same cohort), Test #2, Test #3 and Test #4. The prostate gland and the peripheral zone (PZ) anatomy were manually delineated with consensus read by a radiologist, except for Test #4 cohorts that had pre-marked glandular anatomy. A Bayesian hyperparameter optimization method was applied to construct the network model (PPZ-SegNet) with a training cohort (Train #1, n = 150) using a five-fold cross validation. The model evaluation was performed on an independent cohort of 283 T2W MRI prostate cases (Test #1 to #4) without any additional tuning. The data cohorts were derived from The Cancer Imaging Archives (TCIA): PROSTATEx Challenge, Prostatectomy, Repeatability studies and PROMISE12-Challenge. The segmentation performance was evaluated by computing the Dice similarity coefficient and Hausdorff distance between the estimated-deep-network identified regions and the radiologist-drawn annotations. The deep network architecture was able to segment the prostate gland anatomy with an average Dice score of 0.86 in Test #1 (n = 192), 0.79 in Test #2 (n = 26), 0.81 in Test #3 (n = 15), and 0.62 in Test #4 (n = 50). We also found the Dice coefficient improved with larger prostate volumes in 3 of the 4 test cohorts. The variation of the Dice scores from different cohorts of test images suggests the necessity of more diverse models that are inclusive of dependencies such as the gland sizes and others, which will enable us to develop a universal network for prostate and PZ segmentation. Our training and evaluation code can be accessed through the link: https://github.com/mariabaldeon/PPZ-SegNet.git.

Inter-Reader Variability Using PI-RADS v2 Versus PI-RADS v2.1: Most New Disagreement Stems from Scores 1 and 2

PURPOSE

To analyze possible differences in the inter-reader variability between PI-RADS version 2 (v2) and version 2.1 (v2.1) for the classification of prostate lesions using multiparametric MRI (mpMRI) of the prostate.

METHODS

In this retrospective and randomized study, 239 annotated and histopathologically correlated prostate lesions (104 positive and 135 negative for prostate cancer) were rated twice by three experienced uroradiologists using PI-RADS v2 and v2.1 with an interval of at least two months between readings. Results were tabulated across readers and reading timepoints and inter-reader variability was determined using Fleiss' kappa (κ). Thereafter, an additional analysis of the data was performed in which PI-RADS scores 1 and 2 were combined, as they have the same clinical consequences.

RESULTS

PI-PI-RADS v2.1 showed better inter-reader agreement in the peripheral zone (PZ), but poorer inter-reader agreement in the transition zone (TZ) (PZ: κ = 0.63 vs. κ = 0.58; TZ: κ = 0.47 vs. κ = 0.57). When PI-RADS scores 1 and 2 were combined, the use of PI-RADS v2.1 resulted in almost perfect inter-reader agreement in the PZ and substantial agreement in the TZ (PZ: κ = 0.81; TZ: κ = 0.80).

CONCLUSION

PI-RADS v2.1 improves inter-reader agreement in the PZ. New differences in inter-reader agreement were mainly the result of the assignment of PI-RADS v2.1 scores 1 and 2 to lesions in the TZ. Combining scores 1 and 2 improved inter-reader agreement both in the TZ and in the PZ, indicating that refined definitions may be warranted for these PI-RADS scores.

KEY POINTS

· PI-RADSv2.1 improves inter-reader agreement in the PZ but not in the TZ.. · New differences derived from PI-RADSv2.1 scores 1 and 2 in the TZ.. · Combined PI-RADSv2.1 scores of 1 and 2 yielded better inter-reader agreement.. · PI-RADSv2.1 appears to provide more precise description of lesions in the PZ.. · Improved inter-reader agreement in the PZ stresses the importance of appropriate lexicon description..

CITATION FORMAT

· Beetz N, Haas M, Baur A et al. Inter-Reader Variability Using PI-RADS v2 Versus PI-RADS v2.1: Most New Disagreement Stems from Scores 1 and 2. Fortschr Röntgenstr 2022; 194: 852 - 861.

MRI and Targeted Biopsy Essential Tools for an Accurate Diagnosis and Treatment Decision Making in Prostate Cancer

Prostate cancer (PCa) is one of the most frequent causes of cancer death worldwide. Historically, diagnosis was based on physical examination, transrectal (TRUS) images, and TRUS biopsy resulting in overdiagnosis and overtreatment. Recently magnetic resonance imaging (MRI) has been identified as an evolving tool in terms of diagnosis, staging, treatment decision, and follow-up. In this review we provide the key studies and concepts of MRI as a promising tool in the diagnosis and management of prostate cancer in the general population and in challenging scenarios, such as anteriorly located lesions, enlarged prostates determining extracapsular extension and seminal vesicle invasion, and prior negative biopsy and the future role of MRI in association with artificial intelligence (AI).

MRI-targeted prostate biopsy: the next step forward!

Aim

For decades, the gold standard technique for diagnosing prostate cancer was the 10 to 12 core systematic transrectal or transperineal biopsy, under ultrasound guidance. Over the past years, an increased rate of false negative results and detection of clinically insignificant prostate cancer has been noted, resulting into overdiagnosis and overtreatment. The purpose of the current study was to evaluate the changes in diagnosis and management of prostate cancer brought by MRI-targeted prostate biopsy.

Methods

A critical review of literature was carried out using the Medline database through a PubMed search, 37 studies meeting the inclusion criteria: prospective studies published in the past 8 years with at least 100 patients per study, which used multiparametric magnetic resonance imaging as guidance for targeted biopsies.

Results

In-Bore MRI targeted biopsy and Fusion targeted biopsy outperform standard systematic biopsy both in terms of overall and clinically significant prostate cancer detection, and ensure a lower detection rate of insignificant prostate cancer, with fewer cores needed. In-Bore MRI targeted biopsy performs better than Fusion biopsy especially in cases of apical lesions.

Conclusion

Targeted biopsy is an emerging and developing technique which offers the needed improvements in diagnosing clinically significant prostate cancer and lowers the incidence of insignificant ones, providing a more accurate selection of the patients for active surveillance and focal therapies.

Assessment of magnetic resonance imaging (MRI)-fusion prostate biopsy with concurrent standard systematic ultrasound-guided biopsy among men requiring repeat biopsy

INTRODUCTION

The role of magnetic resonance imaging (MRI)-fusion biopsy (FB) remains unclear in men with prior negative prostate biopsies. This study aimed to compare the diagnostic accuracy of FB with concurrent systematic biopsy (SB) in patients requiring repeat prostate biopsies.

METHODS

Patients with previous negative prostate biopsies requiring repeat biopsies were included. Those without suspicious lesions (≥Prostate Imaging-Reporting and Data System [PI-RADS] 3) on MRI were excluded. All patients underwent FB followed by SB. The primary outcome was the sensitivity for clinically significant prostate cancer (Gleason score ≥7). The secondary objective was identification of potential predictive factors of biopsy performance.

RESULTS

A total of 53 patients were included; 41 (77%) patients were found to have clinically significant prostate cancer. FB had a higher detection rate of significant cancer compared to SB (85% vs. 76%, respectively, p=0.20) and lower diagnosis of indolent (Gleason score 3+3=6) cancer (10% vs. 27%, respectively, p=0.05). FB alone missed six (15%) clinically significant cancers, compared to 10 (24%) with SB. SB performance was significantly impaired in patients with anterior lesions and high prostate volumes (p<0.05). There was high degree of pathological discordance between the two approaches, with concordance seen in only 34% of patients.

CONCLUSIONS

In patients with prior negative biopsies and ongoing suspicion for prostate cancer, a combined approach of FB with SB is needed for optimal detection and risk classification of clinically significant disease. Anterior tumors and large prostates were significant predictors of poor SB performance and an MRI-fusion alone approach in these settings could be considered.

Factors associated with higher prostate biopsy yield: when is software-assisted fusion MRI-targeting necessary?

OBJECTIVE

To evaluate the addition of software-assisted fusion magnetic resonance imaging (MRI) targeted biopsy to systematic biopsy and determine clinical and imaging factors associated with improved prostate cancer (PCa) detection.

METHODS

We analyzed 454 patients who had prostate MRI and underwent combined systematic and software-assisted fusion MRI-targeted biopsy at 2 academic centers between July 2015 and December 2017. For our analysis, we compared the Gleason grade group of cores obtained systematically to cores obtained using MRI-targeting. Using multivariable analysis, we examined clinical and imaging factors associated with higher grade group disease in MRI-targeted cores.

RESULTS

Software assisted fusion MRI-targeted biopsy detected higher grade group disease in 18.3% of patients. Factors associated with higher grade group disease in MRI-targeted cores included anterior MRI lesion location (odds ratio [OR] 3.15, P< 0.01) and multiple lesions on MRI (OR 2.47, P = 0.01). Increasing prostate volume per cubic centimeter was noted to be negatively associated (OR 0.98, P = 0.02). Notably, factors not found to be associated with improved detection included PIRADS classification 5 compared to 3 (OR 2.47, P = 0.08), PIRADS classification 4 compared to 3 (OR 1.37, P = 0.50), previous negative biopsy (OR 1.48, P = 0.29), inclusion on an active surveillance protocol (OR 1.36, P = 0.48), transitional zone lesion location (OR 0.72, P = 0.45), and institution at which biopsy was performed (OR 1.81, P = 0.16).

CONCLUSION

Adding software-assisted fusion MRI-targeting to systematic prostate biopsy offers benefit for men with an anterior and multiple MRI lesions. In absence of these factors, systematic biopsy alone or with cognitive fusion may be considered.

Systematic sampling during MRI-US fusion prostate biopsy can overcome errors of targeting-prospective single center experience after 300 cases in first biopsy setting

Background

Multiparametric magnetic resonance imaging (mpMRI) and targeted biopsy have become an integral part of the diagnosis of prostate cancer (PCa), as recommended by the European Association of Urology Guidelines. The aim of the current study was to evaluate the performance of MRI and MRI-transrectal ultrasound (TRUS) fusion prostate biopsy as first biopsy setting in a tertiary center.

Methods

A cohort of 300 patients was included in the current analysis. All patients presented with clinical or biochemical suspicion of PCa and harbored at least one suspect lesion on mpMRI. MRI-TRUS fusion prostate biopsy, followed by 12 core systematic prostate biopsy were performed by the same operator using a rigid registration system.

Results

The mean age of the patients was 64 years (IQR: 58–68.5 years) and the mean PSA was 6.35 ng/mL (IQR: 4.84–9.46 ng/mL). Overall cancer and csPCa diagnosis rates were 47% and 40.66%. Overall PCa/csPCa detection rates were 20.4%/11.1%, 52%/45% and 68.5%/66.7% for PI-RADS lesions 3, 4 and 5 (P<0.001/P<0.0001). Larger lesion diameter and lesion volume were associated with PCa diagnosis (P=0.006 and P=0.001, respectively). MRI-TRUS fusion biopsy missed PCa diagnosis in 37 cases (of whom 48.6% ISUP 1) in comparison with 9 patients missed by systematic biopsy (of whom 11.1% ISUP 1). In terms of csPCa, systematic biopsy missed 77.7% of the tumors located in the anterior and transitional areas. The rate of csPCa was highest when targeted biopsy was associated with systematic biopsy: 86.52% vs. 68.79% for targeted biopsy vs. 80.14% for systematic biopsy, P=0.0004. In 60.6% of cases, systematic biopsy was positive for PCa at the same site as the targeted lesion. Of these patients, eight harbored csPCa and were diagnosed exclusively on systematic biopsy.

Conclusions

MRI-TRUS fusion prostate biopsy improves the diagnosis of csPCa. The main advantage of an MRI-guided approach is the diagnosis of anterior and transitional area tumors. The best results in terms of csPCa diagnosis are obtained by the combination of MRI-TRUS fusion with systematic biopsy. The systematic biopsy performed during MRI-targeted biopsy could have an important role in overcoming errors of MRI-TRUS fusion systems.

MRI-targeted biopsy versus standard transrectal ultrasound-guided biopsy: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

For men with a suspicion of prostate cancer (PCa), the transrectal ultrasound-guided biopsy (TRUS-Bx) was recommended. Multi-parametric magnetic resonance imaging (mp-MRI) could be more useful to more accurately selected patients who are with a clinical suspicion of PCa and eligible for biopsy, and avoid a biopsy if the result was negative. In the present study, we compared the MRI-targeted biopsy (MRI-TBx) with TRUS-Bx.

METHODS

We searched the following online database: PubMed, Embase, and Cochrane Library, and the search was updated to March 2019.

RESULTS

Finally, a total of 8 randomized controlled trials (RCTs) comprising 2593 patients were enrolled in the final analysis. MRI-TBx and TRUS-Bx did not significantly differ in overall PCa (RR = 1.30; 95% CI 0.98-1.72; P = 0.067), clinically significant PCa (RR = 1.35; 95% CI 0.98-1.86; P = 0.065), and clinically insignificant PCa (RR = 0.76; 95% CI 0.40-1.46; P = 0.416). While in patients with initial biopsy, MRI-TBx had a significantly higher detection rate of overall PCa (RR = 1.40; 95% CI 1.01-1.94; P = 0.045).

CONCLUSION

In the present study, we found that MRI-TBx potentially benefits the detection of overall and clinically significant PCa compared with TRUS-Bx in patients with a suspicion of PCa. Furthermore, in patients with initial biopsy, MRI-TBx had a significantly higher detection rate of overall PCa and a potentially higher detection rate of clinically significant PCa. While for patients with prior negative biopsy, we did not detect significant differences in overall and clinically significant PCa between two groups. More large and multicenter RCTs are further required.

Apical periurethral transition zone lesions: MRI and histology findings

PURPOSE

Apical periurethral transition zone (TZ) cancers can pose unique problems for surgery and radiation therapy. Here, we describe the appearance of such cancers on multiparametric MRI (mpMRI) and correlate this with histopathology derived from MRI-targeted biopsy.

MATERIALS AND METHODS

Between May 2011 and January 2019, a total of 4381 consecutive patients underwent 3 T mpMRI. Of these, 53 patients with 58 apical periurethral TZ lesions underwent TRUS/MRI fusion-guided biopsy and 12-core systematic TRUS-guided biopsy. Correlation was made with patient age, PSA, PSA density, whole prostate volume, and Gleason scores.

RESULTS

A total 53 men (median age 68 years, median PSA 7.94 ng/ml) were identified as having at least one apical periurethral TZ lesion on mpMRI and 5 (9%) patients had more than one apical periurethral lesion. Thus, 58 lesions were identified in 53 patients. Of these 37/53 patients (69%) and 40/58 lesions were positive at biopsy for prostate cancer. Seven were diagnosed by 12-core systematic TRUS-guided biopsy and 34 were diagnosed by TRUS/MRI fusion-guided biopsy. Gleason score was ≥ 3 + 4 in 34/58 (58%) lesions.

CONCLUSION

Identification of apical periurethral TZ prostate cancers is important to help guide surgical and radiation therapy as these tumors are adjacent to critical structures. Because of the tendency to undersample the periurethral zone during TRUS biopsy, MRI-guided biopsy is particularly helpful for detecting apical periurethral TZ prostate cancers many of which prove to be clinically significant.

Efficacy of 3T Multiparametric MR Imaging followed by 3T in-Bore MR-Guided Biopsy for Detection of Clinically Significant Prostate Cancer Based on PIRADSv2.1 Score

PURPOSE

To evaluate the diagnostic yield of 3T in-Bore magnetic resonance-guided biopsy (3T IB-MRGB) for detection of clinically significant prostate cancer (csPCa), based on assessment using the Prostate Imaging Reporting and Data System version 2.1 (PIRADSv2.1).

MATERIALS AND METHODS

This single-center study examined individuals who underwent 3T multiparametric prostate magnetic resonance (MR) imaging and subsequent 3T IB-MRGB. The final study cohort included 379 men (with 475 targets) divided into 3 subcohorts: biopsy-naïve men (n = 123), individuals with a history of negative trans-rectal-ultrasonography (TRUS) biopsy results (n = 106), and men with low-grade PCa under active surveillance (n = 150). csPCa was defined as having a Gleason score (GS) ≥3+4.

RESULTS

3T IB-MRGB detected PCa and csPCa in 69.1% (262 of 379) and 50.3% (193 of 379) of patients, respectively. The PCa and csPCa detection rates per target were 64.2% (305 of 475) and 43.8% (208 of 475), respectively. The rate of urosepsis, treated with intravenous antibiotics, was 1% (4 patients). In TRUS biopsy negative results and biopsy-naïve subcohorts, csPCa was found in 36.8% (39 of 106) and 52.8% (65 of 123), respectively. In 50.7% (76 of 150) of the active surveillance subcohort, 3T IB-MRGB upgraded the GS assigned in prior TRUS biopsies. Positive predictive values of PIRADSv2.1 categories 3, 4, and 5 for csPCa detection were 24.8%, 44.4%, and 67.1%, respectively. Higher PIRADSv2.1 categories were significantly associated with PCa (odds ratio [OR], 3.97; 95% confidence interval [CI], 2.98-5.28) and csPCa (OR, 1.41; 95% CI, 1.03-1.94) detection. Of 137 PIRADSv2 category 3 lesions, 28 were downgraded to PIRADSv2.1 category 2, in which there were no occurrences of csPCa in histology.

CONCLUSIONS

Use of 3T IB-MRGB resulted in detection of csPCa in 50.9% of individuals. 3T IB-MRGB has a high diagnostic yield in individuals with negative TRUS biopsy results and those under active surveillance. The PIRADSv2.1 category is a strong predictor of PCa and csPCa detection.

3-T Multiparametric MRI Followed by In-Bore MR-Guided Biopsy for Detecting Clinically Significant Prostate Cancer After Prior Negative Transrectal Ultrasound-Guided Biopsy

OBJECTIVE. The purpose of this study was to evaluate the rate of detection of clinically significant prostate cancer (csPCa), as assessed on the basis of Prostate Imaging Reporting and Data System version 2.1 (PI-RADSv2.1) guidelines, using 3-T in-bore MR-guided biopsy (MRGB) for a cohort of patients suspected of having csPCa despite having a history of recent negative transrectal ultrasound-guided biopsy results. MATERIALS AND METHODS. The cohort in this retrospective, single-center study was derived from a database of 330 patients who underwent multiparametric MRI (mpMRI) followed by in-bore transrectal 3-T MRGB. Seventy-nine patients (mean [± SD] age, 64.1 ± 8.6 years) with prior negative transrectal ultrasound-guided biopsy results and positive pre-MRGB mpMRI results (PI-RADS score ≥ 3) composed the final cohort. The rate of detection of PCa and csPCa (the latter of which was defined by a Gleason score of 3 + 4 or higher) was stratified according to updated PI-RADSv2.1 assessment. RESULTS. MRGB detected PCa in 36 patients (45.6%), 30 (83.3%) of whom had csPCa. The PI-RADSv2.1 score was a strong predictor (odds ratio, 3.97; 95% CI, 1.93-7.47) of csPCa detection. We found two benign transition zone target lesions that were downgraded from PI-RADSv2 category 3 to PI-RADSv2.1 category 2. PCa was detected in 18.4% (7/38), 65.2% (15/23), and 87.5% (14/16) of individuals with PI-RADSv2.1 category 3, 4, and 5 lesions, respectively, with 85.7% (6/7), 86.7% (13/15), and 78.6% (11/14) of these cases found to be csPCa, respectively. Of the seven PI-RADSv2.1 category 3 csPCa lesions, six had prostate-specific antigen density greater than 0.10 ng/mL/cc. CONCLUSION. With the use of 3-T in-bore MRGB, csPCa was detected in 38% of individuals with prior negative transrectal ultrasound-guided biopsy results. PI-RADSv2.1 was a strong predictor of csPCa detection. On the basis of our results, patients with PI-RADSv2.1 category 4 or 5 lesions and patients with PI-RADSv2.1 category 3 lesions and a prostate-specific antigen density greater than or equal to 0.10 ng/mL/cc may benefit from in-bore MRGB.

Prognostic performance of magnetic resonance imaging-guided biopsy in defining prostate cancer anterior lesions

PURPOSE

Diagnosis of anterior prostate cancer (PCa) can be quite challenging, often leading to delay in treatment. mpMRI-guided biopsy (GB) has been introduced aiming to increase the number of diagnoses of clinically significant PCa with fewer cores. The aim of our study is to compare pathological findings of prostate biopsy, In-bore or Fusion technique, with histopathological evaluation of radical prostatectomy.

METHODS

We prospectively collected data from 90 consecutive patients who underwent either In-bore or Fusion biopsy following the detection of an index suspicious lesion at mpMRI in the anterior part of the prostatic gland. Bioptical pathological findings were compared with pathological findings reported after robot-assisted radical prostatectomy.

RESULTS

Patients who underwent In-bore GB had a higher rate of previous negative prostate biopsies (19% vs 44%, p = 0.02). Median number of bioptic cores taken (13 vs 2) and number of positive cores (3 vs 2) were significantly superior in the Fusion group compared to the In-bore group (p < 0.001 and p = 0.002, respectively), whilst clinical International Society of Urological Pathology (ISUP) grade was homogeneous within groups. The concordance between anterior lesions detected at biopsy and those reported in the histopathological finding of radical prostatectomy was very high, without statistically significant difference between groups.

CONCLUSION

Both Fusion and In-bore GB are accurate in detecting anterior PCa, with enhanced precision detecting clinically significant tumours, as evidenced by pathologic examinations which confirmed the presence of index anterior PCa in > 50% of patients overall. Additional sextant biopsy is still required, especially among biopsy-näive patients, to avoid missing clinically significant PCa.

MRI/TRUS fusion vs. systematic biopsy: intra-patient comparison of diagnostic accuracy for prostate cancer using PI-RADS v2

OBJECTIVE

To evaluate the efficacy of multiparametric magnetic resonance/transrectal ultrasound fusion (MRI/TRUS fusion) biopsy versus systematic biopsy and its association with PI-RADS v2 categories in patients with suspected prostate cancer.

MATERIALS AND METHODS

122 patients undergoing both MRI/TRUS fusion and systematic biopsy, with suspicion of prostate cancer, with suspicious findings on MRI based on PI-RADS v2, were included between April 2016 and March 2017. Comparison of tumor detection rates using each technique and combined techniques was performed for all lesions as well as those that are traditionally difficult to access (i.e., anterior lesions).

RESULTS

Prostate cancer was detected in 83/122 patients (68%) with 74.6% clinically significant lesions (Gleason 3 + 4 or greater). There was a statistically significant difference in presence of clinically significant prostate cancer in PI-RADS v2 categories of 3, 4, and 5 (20%, 52% and 77%, respectively, p < 0.001). Fusion biopsy was positive in a significantly higher percentage of patients versus systematic biopsy (56% versus 48%, respectively, p < 0.05). The fusion biopsy alone was positive in 20%. Of 34 patients with anterior lesions on MRI, 44% were detected only by fusion biopsy, with a joint yield of 71%. In patients with previous negative systematic biopsies, 48.7% lesions were found by fusion biopsy with 20.5% being exclusively positive by this method. The percentage of positive cores for fusion biopsies was significantly higher than for systematic biopsies (26% vs. 12.3%, p < 0.001).

CONCLUSION

The incorporation of MRI/TRUS fusion biopsy significantly improves the detection rate of prostate cancer versus systematic biopsy, particularly for anterior lesions.

Negative Biopsy Histology in Men With PI-RADS Score 5 in Daily Clinical Practice: Incidence of Granulomatous Prostatitis

INTRODUCTION

The purpose of this study was to evaluate the biopsy histology of men who underwent transperineal multi-parametric magnetic resonance imaging (mpMRI)/transrectal ultrasound fusion biopsy for Prostate Imaging Reporting and Data System (PI-RADS) score 5 lesions.

PATIENTS AND METHODS

From January 2016 to June 2019, 105 men with PI-RADS score 5 underwent mpMRI/transrectal ultrasound fusion biopsy combined with systematic prostate biopsy. All the patients underwent a 3.0 Tesla pelvic mpMRI for the first time before prostate biopsy. In detail, the detection rate for clinically significant prostate cancer (PCa) and the follow-up of the patients without proven diagnosis of PCa has been reported.

RESULTS

In 91 (86.7%) of 105 patients, a stage T1c PCa was diagnosed, and 89 (84.5%) of 105 of them were classified as clinically significant PCa. Among the 16 (15.5%) of 105 patients with absence of cancer, 5 (31.5%) of 16 had an aspecific granulomatous prostatitis, 1 (6.2%) of 16 had a specific granulomatous prostatitis secondary to prostatic Mycobacterium Tubercolosis, and 10 (62.3%) of 16 had a diagnosis of normal parenchyma. The 6 patients with granulomatous prostatitis underwent specific antibiotic therapy followed by laboratory (ie, semen and urine cultures) and clinical evaluation. Six months from prostate biopsy, none of the 16 patients underwent repeat prostate biopsy because prostate-specific antigen (PSA) (15/16 cases) plus PSA density significantly decreased; in addition, in all the cases the initial PI-RADS score 5 was downgraded at mpMRI revaluation to PI-RADS score ≤ 3.

CONCLUSION

The reduction of PSA plus PSA density values and the downgrading of PI-RADS score to ≤ 3 allow avoiding a repeated prostate biopsy in men with initial mpMRI PI-RADS score 5 lesion and negative biopsy histology.

Magnetic Resonance Imaging-targeted Biopsy Versus Systematic Biopsy in the Detection of Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

Magnetic resonance imaging (MRI)-targeted prostate biopsy (MRI-TB) may be an alternative to systematic biopsy for diagnosing prostate cancer.

OBJECTIVE

The primary aims of this systematic review and meta-analysis were to compare the detection rates of clinically significant and clinically insignificant cancer by MRI-TB with those by systematic biopsy in men undergoing prostate biopsy to identify prostate cancer.

EVIDENCE ACQUISITION

A literature search was conducted using the PubMed, Embase, Web of Science, Cochrane library, and Clinicaltrials.gov databases. We included prospective and retrospective paired studies where the index test was MRI-TB and the comparator test was systematic biopsy. We also included randomised controlled trials (RCTs) if one arm included MRI-TB and another arm included systematic biopsy. The risk of bias was assessed using a modified Quality Assessment of Diagnostic Accuracy Studies-2 checklist. In addition, the Cochrane risk of bias 2.0 tool was used for RCTs.

EVIDENCE SYNTHESIS

We included 68 studies with a paired design and eight RCTs, comprising a total of 14709 men who either received both MRI-TB and systematic biopsy, or were randomised to receive one of the tests. MRI-TB detected more men with clinically significant cancer than systematic biopsy (detection ratio [DR] 1.16 [95% confidence interval {CI} 1.09-1.24], p<0.0001) and fewer men with clinically insignificant cancer than systematic biopsy (DR 0.66 [95% CI 0.57-0.76], p<0.0001). The proportion of cores positive for cancer was greater for MRI-TB than for systematic biopsy (relative risk 3.17 [95% CI 2.82-3.56], p<0.0001).

CONCLUSIONS

MRI-TB is an attractive alternative diagnostic strategy to systematic biopsy.

PATIENT SUMMARY

We evaluated the published literature, comparing two methods of diagnosing prostate cancer. We found that biopsies targeted to suspicious areas on magnetic resonance imaging were better at detecting prostate cancer that needs to be treated and avoiding the diagnosis of disease that does not need treatment than the traditional systematic biopsy.

Use of multiparametric magnetic resonance imaging and fusion-guided biopsies to properly select and follow African-American men on active surveillance

OBJECTIVES

To determine the rate of Gleason Grade Group (GGG) upgrading in African-American (AA) men with a prior diagnosis of low-grade prostate cancer (GGG 1 or GGG 2) on 12-core systematic biopsy (SB) after multiparametric magnetic resonance imaging (mpMRI) and fusion biopsy (FB); and whether AA men who continued active surveillance (AS) after mpMRI and FB fared differently than a predominantly Caucasian (non-AA) population.

PATIENTS AND METHODS

A database of men who had undergone mpMRI and FB was queried to determine rates of upgrading by FB amongst men deemed to be AS candidates based on SB prior to referral. After FB, Kaplan-Meier curves were generated for AA men and non-AA men who then elected AS. The time to GGG upgrading and time continuing AS were compared using the log-rank test.

RESULTS

AA men referred with GGG 1 disease on previous SB were upgraded to GGG ≥3 by FB more often than non-AA men, 22.2% vs 12.7% (P = 0.01). A total of 32 AA men and 258 non-AA men then continued AS, with a median (interquartile range) follow-up of 39.19 (24.24-56.41) months. The median time to progression was 59.7 and 60.5 months, respectively (P = 0.26). The median time continuing AS was 61.9 months and not reached, respectively (P = 0.80).

CONCLUSIONS

AA men were more likely to be upgraded from GGG 1 on SB to GGG ≥3 on initial FB; however, AA and non-AA men on AS subsequently progressed at similar rates following mpMRI and FB. A greater tendency for SB to underestimate tumour grade in AA men may explain prior studies that have shown AA men to be at higher risk of progression during AS.

Comparison of diagnostic value of multi-slice spiral CT and MRI for different pathological stages of prostate cancer

Diagnostic value of magnetic resonance imaging (MRI) and multi-slice spiral CT (MSCT) for different pathological stages of prostate cancer was compared. A total of 112 patients with prostate cancer who underwent surgical pathology in The Affiliated Yantai Yuhuangding Hospital of Qingdao University from February 2014 to January 2016 were enrolled as prostate cancer group, and another 100 patients who received physical health examinations during the same period as the normal group. MSCT and MRI scanning were performed on patients in both groups to analyze their diagnostic value for stages A/B and C/D of prostate cancer. Based on the apparent diffusion coefficient (ADC) value generated by the diffusion-weighted imaging (DWI) in MRI, there was a significant difference in the ADC value between different stages of prostate cancer (P<0.05); the pathological stage was negatively correlated with the ADC value (r=−0.7629, P<0.05), and the higher the stage was, the lower the ADC value was. The sensitivity was significantly higher in the MRI group than that in the MSCT group (92.0 vs. 79.5%, P<0.05), and the specificity was significantly higher in the MRI group than that in the MSCT group (90.0 vs. 70.0%, P<0.05). In the diagnosis of stage A and B of prostate cancer, the diagnostic coincidence rate was 86.7% in the MRI group, and 57.8% in the MSCT group (P<0.05); the misdiagnosis rate and missed diagnosis rate were significantly lower in the MRI group than those in the MSCT group (P<0.05). The accuracy of MRI is higher than that of MSCT in the diagnosis of early prostate cancer. Both MRI and MSCT can accurately detect stages C and D of prostate cancer, but the ADC value in MRI has great clinical significance for judging the risk of the tumor. Therefore, MRI is more valuable than MSCT in the diagnosis of patients with different pathological stages of prostate cancer.

Rethinking active surveillance for prostate cancer in African American men

Active surveillance (AS) is a treatment modality for prostate cancer that aims to simultaneously avoid overtreatment and allow for the timely intervention of localized disease. AS has become the de facto standard of care for most men with low-risk prostate cancer. However, few African American (AA) men were included in the prospective observational cohorts that resulted in a paradigm shift in treatment recommendations from active intervention toward AS. It has been established that AA men have an increased prostate cancer incidence, higher baseline prostate-specific antigen (PSA) values, more aggressive prostate cancer features, greater frequency of biochemical recurrence after treatment, and higher overall cancer-specific mortality compared to their Caucasian counterparts. As such, this has given many physicians pause before initiating AS for AA patients. In the following manuscript, we will review the available literature regarding AS, with a particular focus on AA men. The preponderance of evidence demonstrates that AS is as viable a management method for AA with low-risk prostate cancer as it is with other racial groups.

Lowering positive margin rates at radical prostatectomy by color coding of biopsy specimens to permit individualized preservation of the neurovascular bundles: is it feasible? a pilot investigation

Objective:

To evaluate whether color-coding of prostate core biopsy specimens aids in preservation of the neurovascular bundles from an oncological perspective.

Materials and Methods:

MRI guided transrectal ultrasound and biopsy of the prostate were performed in 51 consecutive patients suspected of being at high risk for harboring prostate cancer. Core specimens were labeled with blue dye at the deep aspect and red dye at the superficial peripheral aspect of the core. The distance from the tumor to the end of the dyed specimen was measured to determine if there was an area of normal tissue between the prostate capsule and tumor.

Results:

Of the 51 patients undergoing prostate biopsy, 30 (58.8%) were found to have cancer of the prostate: grade group 1 in 13.7%, 2 in 25.5%, 3 in 7.8%, 4 in 7.8% and 5 in 3.9% of the cohort. A total of 461 cores were analyzed in the cohort, of which 122 showed cancer. Five patients opted to undergo robotic assisted laparoscopic radical prostatectomy. No patients had a positive surgical margin (PSM) or extra prostatic extension (EPE) on radical prostatectomy if there was a margin of normal prostatic tissue seen between the dye and the tumor on prostate biopsy.

Conclusion:

Color-coding of prostate biopsy core specimens may assist in tailoring the approach for preservation of the neurovascular bundles without compromising early oncological efficacy. Further study is required to determine whether this simple modification of the prostate biopsy protocol is valuable in larger groups of patients.

Targets missed: predictors of MRI-targeted biopsy failing to accurately localize prostate cancer found on systematic biopsy

BACKGROUND

Magnetic resonance imaging (MRI)/ultrasound (US) fusion-guided biopsy has improved the ability to localize and detect prostate cancer (PCa) with efficiency surpassing systematic biopsy. Nevertheless, some patients have PCa missed using the MRI-targeted biopsy sampling alone. We aim to identify clinical and imaging parameters associated with cases where targeted biopsy did not detect PCa compared to systematic biopsy.

METHODS

We conducted a retrospective review of patients who underwent MRI/US fusion-guided biopsy in addition to concurrent systematic, extended-sextant biopsy between 2014 and 2017. For patients with PCa detected on systematic biopsy not properly localized by MRI/US fusion-guided biopsy, the sextant distance from MRI-targeted lesion to the cancer-positive sextant was calculated and parameters potentially predicting this targeting miss were evaluated.

RESULTS

In all, 35/127 (27.6%) patients with single-session MRI/US fusion-guided biopsy plus standard biopsy finding PCa had lesions incorrectly localized. Of these, 15/35 (42.9%) were identified as possible fusion-software misregistrations. The remainder, 12/35 (34.3%), represented targeted biopsies one sextant away from the cancer focus and 8/35 (22.9%) targeted biopsies two sextants away from the cancer focus. Only 7/35 (20.0%) patients were determined to have clinically significant PCa, which represents 7/127 (5.5%) of the overall population. Lower MRI lesion volumes (p = 0.022), lesion density (p < 0.001), and PI-RADS scores (p < 0.001) were significantly associated with targeted biopsy missing PCa detected on systematic biopsy.

CONCLUSION

Clinically significant PCa is rarely missed utilizing MRI/US fusion-guided biopsy. With the majority of missed tumors representing targeting misregistrations or cases of low-grade cancer in sextants immediately adjacent to MRI suspicious lesions. Lower MRI lesion volumes, lesion density, and PI-RADS are predictors of cases with targeted biopsies missing cancer, for which systematic sampling of the sextants containing MRI targets and adjacent sextants would most optimize PCa detection.

Prostate Cancers Detected by Magnetic Resonance Imaging–Targeted Biopsies Have a Higher Percentage of Gleason Pattern 4 Component and Are Less Likely to Be Upgraded in Radical Prostatectomies

Context.—

In Gleason score (GS) 7 prostate cancers, the quantity of Gleason pattern 4 (GP 4) is an important prognostic factor and influences treatment decisions. Magnetic resonance imaging (MRI)–targeted biopsy has been increasingly used in clinical practice.

Objective.—

To investigate whether MRI-targeted biopsy may detect GS 7 prostate cancer with greater GP 4 quantity, and whether it improves biopsy/radical prostatectomy GS concordance.

Design.—

A total of 243 patients with paired standard and MRI-targeted biopsies with cancer in either standard or targeted or both were studied, 65 of whom had subsequent radical prostatectomy. The biopsy findings, including GS and tumor volume, were correlated with the radical prostatectomy findings.

Results.—

More prostate cancers detected by MRI-targeted biopsy were GS 7 or higher. Mean GP 4 percentage in GS 7 cancers was 31.0% ± 29.3% by MRI-targeted biopsy versus 25.1% ± 29.5% by standard biopsy. A total of 122 of 218 (56.0%) and 96 of 217 (44.2%) prostate cancers diagnosed on targeted biopsy and standard biopsy, respectively, had a GP 4 of 10% or greater (P = .01). Gleason upgrading was seen in 12 of 59 cases (20.3%) from MRI-targeted biopsy and in 24 of 57 cases (42.1%) from standard biopsy (P = .01). Gleason upgrading correlated with the biopsy cancer volume inversely and GP 4 of 30% or less in standard biopsy. Such correlation was not found in MRI-targeted biopsy.

Conclusions.—

Magnetic resonance imaging–targeted biopsy may detect more aggressive prostate cancers and reduce the risk of Gleason upgrading in radical prostatectomy. This study supports a potential role for MRI-targeted biopsy in the workup of prostate cancer and inclusion of percentage of GP 4 in prostate biopsy reports.

Beyond transrectal ultrasound-guided prostate biopsies: available techniques and approaches

OBJECTIVES

Recent advances have led to the use of magnetic resonance imaging (MRI) alone or with fusion to transrectal ultrasound (TRUS) images for guiding biopsy of the prostate. Our group sought to develop consensus recommendations regarding MRI-guided prostate biopsy based on currently available literature and expert opinion.

METHODS

The published literature on the subject of MRI-guided prostate biopsy was reviewed using standard search terms and synthesized and analyzed by four different subgroups from among the authors. The literature was grouped into four categories-MRI-guided biopsy platforms, robotic MRI-TRUS fusion biopsy, template mapping biopsy and transrectal MRI-TRUS fusion biopsy. Consensus recommendations were developed using the Oxford Center for Evidence Based Medicine criteria.

RESULTS

There is limited high level evidence available on the subject of MRI-guided prostate biopsy. MRI guidance with or without TRUS fusion can lead to fewer unnecessary biopsies, help identify high-risk (Gleason ≥ 3 + 4) cancers that might have been missed on standard TRUS biopsy and identify cancers in the anterior prostate. There is no apparent significant difference between MRI biopsy platforms. Template mapping biopsy is perhaps the most accurate method of assessing volume and grade of tumor but is accompanied by higher incidence of side effects compared to TRUS biopsy.

CONCLUSIONS

Magnetic resonance imaging-guided biopsies are feasible and better than traditional ultrasound-guided biopsies for detecting high-risk prostate cancer and anterior lesions. Judicious use of MRI-guided biopsy could enhance diagnosis of clinically significant prostate cancer while limiting diagnosis of insignificant cancer.

Anterior Localization of Prostate Cancer Suspicious Lesions in 1,161 Patients Undergoing Magnetic Resonance Imaging/Ultrasound Fusion Guided Targeted Biopsies

PURPOSE

Based on findings in transrectal ultrasound guided biopsy series standard sampling of the prostate targets the posterior/peripheral zone. However, a substantial proportion of lesions that are prostate cancer suspicious and PI-RADS™ (Prostate Imaging Reporting and Data System) 3 or greater on magnetic resonance imaging is located in the anterior segment of the prostate, requiring deeper placement and targeting of the biopsy needle.

MATERIALS AND METHODS

Overall 1,161 patients underwent magnetic resonance imaging/ultrasound fusion guided targeted biopsy. Prostate cancer suspicious lesions on magnetic resonance imaging were dichotomized into anterior vs posterior prostate segments. Patients were stratified by the number of prior negative systematic biopsy sessions. Descriptive statistics included the frequency and proportion of multiparametric magnetic resonance imaging findings and corresponding histological results.

RESULTS

Targeted biopsy was performed in 513 patients (44%) who were systematic biopsy naïve, 396 (34%) with 1 prior negative systematic biopsy and 252 (22%) with 2 or more prior negative systematic biopsies. When patients were stratified by the number of prior systematic biopsy sessions, the proportion with exclusively anterior, PI-RADS 3 or greater lesions on magnetic resonance imaging increased from 3.5% to 9.1% (p = 0.006). Unfavorable 3 + 4 and 4 + 3 or greater primary Gleason patterns were identified in exclusively anterior vs posterior lesions in 31% vs 21% of the 448 patients, of whom 64 had exclusively anterior and 384 had posterior PI-RADS 3 or greater lesions, respectively, on magnetic resonance imaging. Multivariable logistic regression analyses confirmed these findings.

CONCLUSIONS

After multiple previous negative systematic biopsy sessions the proportion of anterior lesions on magnetic resonance imaging increased. Such lesions harbored a greater amount of unfavorable prostate cancer. Therefore, image guidance for precise targeting should be considered, especially after initially negative transrectal ultrasound guided systematic biopsy.

MRI Robots for Needle-Based Interventions: Systems and Technology

Magnetic resonance imaging (MRI) provides high-quality soft-tissue images of anatomical structures and radiation free imaging. The research community has focused on establishing new workflows, developing new technology, and creating robotic devices to change an MRI room from a solely diagnostic room to an interventional suite, where diagnosis and intervention can both be done in the same room. Closed bore MRI scanners provide limited access for interventional procedures using intraoperative imaging. MRI robots could improve access and procedure accuracy. Different research groups have focused on different technology aspects and anatomical structures. This paper presents the results of a systematic search of MRI robots for needle-based interventions. We report the most recent advances in the field, present relevant technologies, and discuss possible future advances. This survey shows that robotic-assisted MRI-guided prostate biopsy has received the most interest from the research community to date. Multiple successful clinical experiments have been reported in recent years that show great promise. However, in general the field of MRI robotic systems is still in the early stage. The continued development of these systems, along with partnerships with commercial vendors to bring this technology to market, is encouraged to create new and improved treatment opportunities for future patients.

Predictors for the detection of prostate cancer and clinically significant prostate cancer using TRUS-guided biopsy in patients with negative initial biopsy results

PURPOSE

We aimed to determine the predictors for the detection of prostate cancer and clinically significant prostate cancer in the setting of repeat prostate biopsy using trans-rectal ultrasonography-guided biopsy.

METHODS

A total of 636 patients who underwent repeat prostate biopsy were included. The patients were divided into two groups according to the repeat biopsy results (with vs. without prostate cancer). A multivariable analysis was performed to assess the predictors for the detection of prostate cancer and clinically significant prostate cancer.

RESULTS

Prostate cancer was detected in 98 patients (15.4%). Although there was no difference in the prostate-specific antigen velocity, the prostate-specific antigen density was higher in the patients with prostate cancer at the initial (0.14 vs. 0.17 ng/mL/cc, p = 0.049) and repeat biopsies (0.17 vs. 0.26 ng/mL/cc, p < 0.001). The proportions of the patients who met the active surveillance criteria were as follows: 22.4% (Johns Hopkins), 30.6% (University of Toronto), 32.7% (University of California at San Francisco), 30.6% (Prostate Cancer Research International Active Surveillance), 27.6% (Memorial Sloan Kettering Cancer Center), and 13.3% (University of Miami). In the multivariable analysis, age, hypoechoic lesion on trans-rectal ultrasonography, and prostate-specific antigen density at the repeat biopsy were the significant predictors for prostate cancer and clinically significant prostate cancer.

CONCLUSIONS

Trans-rectal ultrasonography before repeat prostate biopsy and the prostate-specific antigen density are useful for selecting patients with a high probability for prostate cancer if repeat trans-rectal ultrasonography-guided biopsy is considered. In addition, these are also helpful for detecting clinically significant prostate cancer.

Incidental findings on multiparametric MRI performed for evaluation of prostate cancer

PURPOSE

Multiparametric magnetic resonance imaging (mp-MRI) and MRI/Ultrasound (US) fusion-guided biopsy are relatively new techniques for improved detection, staging, and active surveillance of prostate cancer (PCa). As with all imaging modalities, MRI reveals incidental findings (IFs) which carry the risk of increased cost, patient anxiety, and iatrogenic morbidity due to workup of IFs. Herein, we report the IFs from 684 MRIs for evaluation of PCa and consider their characteristics and clinical significance.

METHODS

Patients underwent mp-MRI prostate protocol incorporating triplanar T2-weighted, diffusion-weighted, and dynamic contrast-enhanced pelvic MRI as well as a post-contrast abdominopelvic MRI with the primary indication of detection or evaluation of PCa. A total of 684 consecutive prostate MRI reports performed in a series of 580 patients were reviewed. All extraprostatic findings reported were logged and then categorized by organ system and potential clinical significance.

RESULTS

There were 349 true IFs found in 233 (40%) of the 580 patients. One hundred nineteen additional extraprostatic findings were unsuspected but directly related to PCa staging, while the 349 IFs were unrelated and thus truly incidental beyond study indication. While the majority of true IFs were non-urologic, only 6.6% of IFs were considered clinically significant, non-urologic findings, and more than a third of MRI reports had urologic IFs not related to PCa.

CONCLUSIONS

Rates of incidental findings on prostate indication MRI are similar to other abdominopelvic imaging studies. However, only 6.6% of the IFs were considered to be clinically significant non-urologic findings. Further investigations are needed to assess downstream workup of these IFs and resulting costs.

A comparison of prostate tumor targeting strategies using magnetic resonance imaging-targeted, transrectal ultrasound-guided fusion biopsy

PURPOSE

Magnetic resonance imaging (MRI)-targeted, three-dimensional (3D) transrectal ultrasound (TRUS)-guided prostate biopsy aims to reduce the 21-47% false-negative rate of clinical two-dimensional (2D) TRUS-guided systematic biopsy, but continues to yield false-negative results. This may be improved via needle target optimization, accounting for guidance system errors and image registration errors. As an initial step toward the goal of optimized prostate biopsy targeting, we investigated how needle delivery error impacts tumor sampling probability for two targeting strategies.

METHODS

We obtained MRI and 3D TRUS images from 49 patients. A radiologist and radiology resident assessed these MR images and contoured 81 suspicious regions, yielding tumor surfaces that were registered to 3D TRUS. The biopsy system's root-mean-squared needle delivery error (RMSE) and systematic error were modeled using an isotropic 3D Gaussian distribution. We investigated two different prostate tumor-targeting strategies using (a) the tumor's centroid and (b) a ring in the lateral-elevational plane. For each simulation, targets were spaced at equal arc lengths on a ring with radius equal to the systematic error magnitude. A total of 1000 biopsy simulations were conducted for each tumor, with RMSE and systematic error magnitudes ranging from 1 to 6 mm. The difference in median tumor sampling probability and probability of obtaining a 50% core involvement was determined for ring vs centroid targeting.

RESULTS

Our simulation results indicate that ring targeting outperformed centroid targeting in situations where systematic error exceeds RMSE. In these instances, we observed statistically significant differences showing 1-32% improvement in sampling probability due to ring targeting. Likewise, we observed statistically significant differences showing 1-39% improvement in 50% core involvement probability due to ring targeting.

CONCLUSIONS

Our results suggest that the optimal targeting scheme for prostate biopsy depends on the relative levels of systematic and random errors in the system. Where systematic error dominates, a ring-targeting scheme may yield improved probability of tumor sampling. The findings presented in this paper may be used to aid in target selection strategies for clinicians performing targeted prostate biopsies on any MRI targeted, 3D TRUS-guided biopsy system and could support earlier diagnosis of prostate cancer while it remains localized to the gland and curable.

Are concurrent systematic cores needed at the time of targeted biopsy in patients with prior negative prostate biopsies?

INTRODUCTION AND OBJECTIVES

MRI-guided targeted biopsies are advised in patients who have undergone an initial series of negative systematic biopsies, in whom prostate cancer (PCa) suspicion remains elevated. The aim of the study was to evaluate whether, in men with prior negative prostate biopsies, systematic cores are also warranted at the time of an MRI-targeted repeat biopsy.

MATERIAL AND METHODS

We enrolled patients with prior negative biopsy undergoing real time MRI/TRUS fusion guided prostate biopsy at our institute between 2014 and 2016. Patients with at least one index lesion on multiparametric MRI were included. All eligible patients underwent both systematic random biopsies (12-14 cores) and targeted biopsies (2-4 cores).

RESULTS

The study included 74 men with a median age of 65 years, PSA level of 9.27ng/mL, and prostatic volume of 45ml. The overall PCa detection rate and the clinically significant cancer detection rate were 56.7% and 39.2%, respectively. Targeted cores demonstrated similar clinically significant PCa detection rate compared to systematic cores (33.8% vs. 28.4%, P=0.38) with significantly less tissue sampling. Indeed, a combination approach was significantly superior to a targeted-only in overall PCa detection (+16.7% overall detection rate, P=0.007). Although differences in clinically significant PCa detection were statistically non-significant (P=0.13), a combination approach did allow detecting 7 extra clinically significant PCas (+13.8%).

CONCLUSIONS

In patients with elevated PSA and prior negative biopsies, concurrent systematic sampling may be needed at the time of targeted biopsy in order to maximize PCa detection rate. Larger studies are needed to validate our findings.

LEVEL OF EVIDENCE

4.

Prostate Magnetic Resonance Imaging Provides Limited Incremental Value Over the Memorial Sloan Kettering Cancer Center Preradical Prostatectomy Nomogram

OBJECTIVE

To examine the incremental value of prostate magnetic resonance imaging (MRI) when used in combination with the currently available preoperative risk stratification tool, the Memorial Sloan Kettering Cancer Center (MSKCC) preradical prostatectomy nomogram.

MATERIALS AND METHODS

We reviewed our institutional database of prostate MRI performed before radical prostatectomy between December 2014 and March 2016 (n = 236). We generated a logistic regression model based on observed final pathology results and the MSKCC nomogram predictions for organ-confined disease, extracapsular extension (ECE), seminal vesicle invasion, and lymph node involvement (LNI) ("MSKCC only"). We then generated a combined regression model incorporating both the MSKCC nomogram prediction with the degree of prostate MRI suspicion ("MSKCC + MRI"). Receiver operating characteristic curves were generated, and the area under the curves (AUCs) were compared.

RESULTS

When independently examining the MSKCC nomogram predicted risk and the degree of prostate MRI suspicion, MRI was a predictor for ECE (odds ratio 2.8, P <.01) and LNI (odds ratio 5.6, P = .01). When examining the "MSKCC + MRI" and "MSKCC only" models, the incremental benefit in risk discrimination from the combined model ("MSKCC + MRI") was not significant for organ-confined disease, ECE, seminal vesicle invasion, or LNI (ΔAUC +0.03, P = .10; ΔAUC +0.03, P = .08; ΔAUC 0.63, P = .63; ΔAUC +0.04, P = .42; respectively).

CONCLUSION

A combined model with prostate MRI and the MSKCC nomogram provides no additional risk discrimination over the MSKCC nomogram-based model alone. Evaluation of prostate MRI as a predictive tool should be performed in combination with, not independent of, these clinical risk stratification models.

Preventing clinical progression and need for treatment in patients on active surveillance for prostate cancer

PURPOSE OF REVIEW

Active surveillance is an established treatment option for men with localized, low-risk prostate cancer (CaP). It entails the postponement of immediate therapy with the option of delayed intervention upon disease progression. The rate of clinical progression and need for treatment on active surveillance is approximately 50% over 15 years. The present review summarizes recent data on current methods, attempting to prevent clinical progression.

RECENT FINDINGS

Patient selection for active surveillance is the first mandatory step required to lower progression. Adherence to active surveillance protocols is critical in making sure patients are monitored well and treated early when progression occurs. Before active surveillance allocation and during active surveillance follow-up, methods involving multiparametric MRI, prostate specific antigen derivatives, biopsy factors, urinary, tissue and genetic markers can be used to prevent clinical progression and/or identify those at risk for progression. Medications such as 5α-reductase inhibitors and others might inhibit disease progression in patients on active surveillance.

SUMMARY

Active surveillance is required because of overdiagnosis, along with our inability to accurately predict individual CaP behavior. Several methods can potentially reduce the risk of CaP progression in patients with active surveillance. However, a measure of uncertainty and fear of progression will always accompany patients with active surveillance and the physicians treating them.

Multi-institutional nomogram predicting benign prostate pathology on magnetic resonance/ultrasound fusion biopsy in men with a prior negative 12-core systematic biopsy

BACKGROUND

Prostate multiparametric magnetic resonance imaging (mpMRI) may be recommended for patients with a prior negative systematic biopsy (SB). However, a proportion of these patients will continue to have no prostate cancer (PCa) identified on magnetic resonance/ultrasound fusion biopsy (FB) despite abnormal mpMRI findings.

METHODS

In this multi-institutional, retrospective study, clinical and mpMRI parameters were assessed for 285 consecutive patients with at least 1 prior negative biopsy who underwent FB for a Prostate Imaging Reporting and Data System (PI-RADS) score of 3 to 5 at the University of Rochester Medical Center from December 2014 to December 2016, or at the University of Alabama at Birmingham from February 2014 to February 2017. Nomograms were generated for predicting benign prostate pathology on both the targeted biopsy and the concurrent SB.

RESULTS

Benign pathology was found in 132 of 285 patients (46.3%). In a multivariate analysis, the predictors of benign prostate pathology on FB were age, prostate-specific antigen, prostate volume, and PI-RADS score. The predicted probabilities were plotted on a receiver operating characteristic curve, and the area under the curve was 0.825. The nomogram demonstrated excellent calibration and a high net benefit in a decision curve analysis. With a theoretical cutoff probability of ≥0.7 used to recommend deferment of FB, 61 of 285 patients (21.4%) would have avoided an unnecessary biopsy, and only 4 of 285 patients (1.4%) with PCa with a Gleason score ≥ 3 + 4 would have been missed.

CONCLUSIONS

False-positive mpMRI examinations may occur in up to 46.3% of patients with a prior negative biopsy. Thus, a multi-institutional nomogram has been developed and validated for predicting benign pathology after FB in patients with a prior negative biopsy, and this may help to reduce the number of unnecessary biopsies in the setting of abnormal mpMRI findings. Cancer 2018;124:278-85. © 2017 American Cancer Society.

Changes in prostate cancer detection rate of MRI-TRUS fusion vs systematic biopsy over time: evidence of a learning curve

BACKGROUND

To determine the effect of urologist and radiologist learning curves and changes in MRI-TRUS fusion platform during 9 years of NCI's experience with multiparametric magnetic resonance imaging (mpMRI)/TRUS fusion biopsy.

METHODS

A prospectively maintained database of patients undergoing mpMRI followed by fusion biopsy (Fbx) and systematic biopsy (Sbx) from 2007 to 2016 was reviewed. The patients were stratified based on the timing of first biopsy. Cohort 1 (7/2007-12/2010) accounted for learning curve. Cohort 2 (1/2011-5/2013) and cohort 3 (5/2013-4/2016) included patients biopsied prior to and after debut of a new software platform, respectively. Clinically significant (CS) disease was defined as Gleason 7 (3+4) or higher. McNemar's test compared cancer detection rates (CDRs) of Sbx and Fbx between time periods.

RESULTS

1528 patients were included in the study with 230, 537 and 761 patients included in three respective cohorts. Median age (interquartile range) was 61.0 (±9.0), 62.0 (±7.3), and 64.0 (±11.0) years in three cohorts, respectively (P<0.001). Fbx and Sbx had comparable CS CDR in cohort 1 (24.8 vs 22.2%, P=0.377). Fbx detected significantly more CS disease compared to Sbx in the following two periods (cohort 2: 31.5 vs 25.0%, P=0.001; cohort 3: 36.4 vs 30.3%, P<0.001) and detected significantly less low risk disease in the same period (cohort 2: 14.5 vs 19.6%, P<0.001; cohort 3: 12.6 vs 16.7%, P<0.001). Even after multivariate adjustment with age, PSA, race, clinical stage and MRI suspicion score, Fbx CS cancer detection increased in successive cohorts (cohort 2: OR 2.23, P=0.043; cohort 3: OR 2.92, P=0.007).

CONCLUSIONS

In the past 9 years, there has been significant improvement in the accuracy of Fbx. Our results show that after an early learning period, Fbx detected higher rates of CS cancer and lower rates of clinically insignificant cancer than Sbx. Software advances allowed for even greater detection of CS disease.

Prostate MRI: a national survey of Urologist's attitudes and perceptions

Introduction

The use of multi-parametric (MP) MRI to diagnose prostate cancer has been the subject of intense research, with many studies showing positive results. The purpose of our study is to better understand the accessibility, role, and perceived accuracy of MP-MRI in practice by surveying practicing urologists.

Materials and Methods

Surveys were sent to 7,400 practicing American Urological Association member physicians with a current email address. The survey asked demographic information and addressed access, accuracy, cost, and role of prostate MRI in clinical practice.

Results

Our survey elicited 276 responses. Respondents felt that limited access and prohibitive cost of MP-MRI limits its use, 72% and 59% respectively. Academic urologists ordered more MP-MRI studies per year than those in private practice (43.3% vs. 21.1%; p<0.001). Urologists who performed more than 30 prostatectomies a year were more likely to feel that an MP-MRI would change their surgical approach (37.5% vs. 19.6%, p-value=0.002). Only 25% of respondents agreed or strongly agreed that MP-MRI should be used in active surveillance. For patients with negative biopsies and elevated PSA, 39% reported MP-MRI to be very useful.

Conclusions

Our study found that MP-MRI use is most prominent among practitioners who are oncology fellowship-trained, practice at academic centers, and perform more than 30 prostatectomies per year. Limited access and prohibitive cost of MP-MRI may limit its utility in practice. Additionally, study participants perceive a lack of accuracy of MP-MRI, which is contrary to the recent literature.

Magnetic resonance imaging detection of prostate cancer in men with previous negative prostate biopsy

Use of transrectal ultrasound guided systematic prostate biopsy has poor diagnostic accuracy for prostate cancer (PCa) detection. Recently multiparametric MRI (mpMRI) of the prostate and MR/US fusion biopsy has been gaining popularity for men who have previously undergone a negative biopsy. We performed PubMed® and Web of Science® searches to identify studies on this subject, particularly focusing on studies consisting of patients who have had at least one previously negative biopsy. Across the literature, when a suspicious lesion is found on mpMRI, MR/US fusion biopsy has consistently demonstrated higher detection rate for any PCa and clinically significant PCa (csPCa) compared to the traditional repeat systematic biopsy (SB) approach. Furthermore, anteriorly located tumors are frequently identified using MR targeted biopsy (TB), suggesting that an MR guided approach allows for increased accuracy for detecting tumors commonly missed by systematic biopsies. We conclude that men with a prior negative biopsy and continued suspicion of PCa should strongly be encouraged to get a prostate mpMRI prior to a repeat biopsy.

MR/US Fusion Technology: What Makes It Tick?

MR/US fusion biopsy has emerged as a significant refinement of traditional prostate cancer diagnostic techniques. Utilizing not only quantitative imaging suspicion information from mpMRI but also the spatial accuracy and three-dimensional localization allows such strategies to specifically sample areas of concern with the gland. As such, diagnostic certainty is markedly improved. In this manuscript, we aim to highlight the multidisciplinary approach (amongst urologists, radiologists, pathologists, imaging technologists, nursing staff, and patients) which is required to launch and maintain a successful prostate imaging program.

Imaging of Prostate Cancer Using 18F-Choline PET/Computed Tomography

¹⁸F-fluorocholine (FCH) PET/computed tomography (CT) is a valuable imaging modality in prostate cancer disease. Probably, its main role is restaging of patients with biochemical recurrence after radical prostatectomy or external beam radiotherapy. ¹⁸F-FCH PET/CT is strengthening its position in the initial staging, biopsy target definition, radiotherapy planning, and therapy monitoring. Gleason score and prostate-specific antigen value, doubling time, and velocity can influence positivity of ¹⁸F-FCH PET/CT. The influence of androgen deprivation therapy on choline uptake is not precisely clarified. Collaboration between nuclear medicine physicians, radiologists, urologists, oncologists, and radiotherapists is crucial to help patients with prostate cancer disease.

Multi-parametric MR imaging of the anterior fibromuscular stroma and its differentiation from prostate cancer

PURPOSE

To describe MP-MRI features of the normal anterior fibromuscular stroma (AFMS) and identify MR imaging findings that can differentiate it from anterior prostate cancer.

METHODS

We reviewed MP-MR images and histopathology of patients who underwent pre-operative MRI and prostatectomy between October 2012 and August 2014. Thirty-seven patients with anterior prostate cancer larger than 5 mm and 40 patients with no anterior cancer were included in this study. After correlation with histology and MR images, the size, symmetry, T2, DWI characteristics, and enhancement pattern of normal AFMS and anterior prostate cancer were compared.

RESULTS

Normal AFMS was hypointense and symmetric on T2-weighted images (37/40, 93%), whereas anterior prostate cancers, while also hypointense on T2-weighted images, were predominantly asymmetric (6/37, 16%) (P < 0.001). On high b-value DWI, AFMS was predominantly hypointense (36/40, 90%), whereas anterior prostate cancers were predominantly hyperintense (30/37, 81%) compared to the normal peripheral zone (P < 0.001). The mean ADC and tenth percentile ADC values of anterior prostate cancers were lower than normal AFMS (7.14 vs. 8.33 (10^-4 mm²/s), P < 0.01) and (5.73 vs. 6.95 (10^-4 mm²/s), P < 0.01), respectively. On DCE-MR images, AFMS demonstrated a type 1 enhancement curve (35/39, 90%), whereas anterior prostate cancers demonstrated only either a type 3 (23/37, 62%) or type 2 enhancement curve (14/37, 38%) (P < 0.001).

CONCLUSIONS

Symmetric T2 appearance, hypointense high b-value DWI signal, relatively higher ADC values, and Type 1 enhancement pattern of the AFMS can be helpful in its differentiation from anterior prostate cancers.

Transperineal prostate biopsies for diagnosis of prostate cancer are well tolerated: a prospective study using patient-reported outcome measures

We aimed to determine short-term patient-reported outcomes in men having general anesthetic transperineal (TP) prostate biopsies. A prospective cohort study was performed in men having a diagnostic TP biopsy. This was done using a validated and adapted questionnaire immediately post-biopsy and at follow-up of between 7 and 14 days across three tertiary referral hospitals with a response rate of 51.6%. Immediately after biopsy 43/201 (21.4%) of men felt light-headed, syncopal, or suffered syncope. Fifty-three percent of men felt discomfort after biopsy (with 95% scoring <5 in a 0-10 scale). Twelve out of 196 men (6.1%) felt pain immediately after the procedure. Despite a high incidence of symptoms (e.g., up to 75% had some hematuria, 47% suffered some pain), it was not a moderate or serious problem for most, apart from hemoejaculate which 31 men suffered. Eleven men needed catheterization (5.5%). There were no inpatient admissions due to complications (hematuria, sepsis). On repeat questioning at a later time point, only 25/199 (12.6%) of men said repeat biopsy would be a significant problem despite a significant and marked reduction in erectile function after the procedure. From this study, we conclude that TP biopsy is well tolerated with similar side effect profiles and attitudes of men to repeat biopsy to men having TRUS biopsies. These data allow informed counseling of men prior to TP biopsy and a benchmark for tolerability with local anesthetic TP biopsies being developed for clinical use.

The prostate cancer prevention trial risk calculator 2.0 performs equally for standard biopsy and MRI/US fusion-guided biopsy

BACKGROUND

The Prostate Cancer Prevention Trial Risk Calculator 2.0 (PCPTRC) is a widely used risk-based calculator used to assess a man's risk of prostate cancer (PCa) before biopsy. This risk calculator was created from data of a patient cohort undergoing a 6-core sextant biopsy, and subsequently validated in men undergoing 12-core systematic biopsy (SBx). The accuracy of the PCPTRC has not been studied in patients undergoing magnetic resonance imaging/ultrasound (MRI/US) fusion-guided biopsy (FBx). We sought to assess the performance of the PCPTRC for straitifying PCa risk in a FBx cohort.

METHODS

A review of a prospective cohort undergoing MRI and FBx/SBx was conducted. Data from consecutive FBx/SBx were collected between August 2007 and February 2014, and PCPTRC scores using the PCPTRC2.0R-code were calculated. The risk of positive biopsy and high-grade cancer (Gleason ⩾7) on biopsy was calculated and compared with overall and high-grade cancer detection rates (CDRs). Receiver operating characteristic curves were generated and the areas under the curves (AUCs) were compared using DeLong's test.

RESULTS

Of 595 men included in the study, PCa was detected in 39% (232) by SBx compared with 48% (287) on combined FBx/SBx biopsy. The PCPTRC AUCs for the CDR were similar (P=0.70) for SBx (0.69) and combined biopsy (0.70). For high-grade disease, AUCs for SBx (0.71) and combined biopsy (0.70) were slightly higher, but were not statistically different (P=0.55).

CONCLUSIONS

In an MRI-screened population of men undergoing FBx, PCPTRC continues to represent a practical method of accurately stratifying PCa risk.